Manufacture of incandescing electric lamps.



No. 660,475. Patented Oct. 23, I900.

W. L. VUELKER'. MANUFACTURE OF INCANDESCING ELECTRIC LAMPS.

(Application filed Nov. 20, 1899) (N0 Model.)

M 1mm THE NORRIS PEYERS co, mmouwo" WASNINOTON, n c.

UNITED STATES PATENT OFFICE.

WILLIAM LAWRENCE VOELKER, OF LONDON, ENGLAND, ASSIGNOR TO THERON CLARKORAWVFORD, OF NEWV YORK, N. Y.

MANUFACTURE OF INCANDESOING ELECTRIC LA M PS SPECIFICATION forming'partof Letters Patent N o. 660,475,-dated October 23, 1900.

Application filed November 20, 1899. Serial No. 737,670. (No model.)

To a. whom it may concern:

Be it known that I, WILLIAM LAwRENon VOELKER, a citizen of the UnitedStates of America,residing at 38 Bernard street,Russell Square, London,England, have invented new and useful Improvements in the Manufacture ofIncandescing Electric Lamps, (in respect whereof I have applied forapatent in Great Britain to bear date October 10, 1899, No. 20,346,) ofwhich the following is a specification.

This invention relates to lamps for lighting by the transmission of anelectric current through a filamentous conductor formed of carbon orother highly-resistant substance and inclosed within a vacuous chamber,my

object being to provide against certain infiuences which tend todisintegrate the conductor, such disintegration having the effect notonly of curtailing the life of the filament, but of diminishing thelighting power of the lamp by reason of the deposit which takes placeupon the internal surface of the inclosing chamber.

A lamp adapted for carrying my invention into effect is illustrated inFigures 1 and 2 of the accompanying drawings, the former being alongitudinal section, while the latter is a transverse section on theline a: 6L, Fig. 1. Fig. 2 is a transverse section on the line y y inFig. 1. In Fig. 3 the filament and its carrier, although included inFig. 1, are illustrated separately.

The lamp comprises a filament A of the well-known U type mounted in avacuous chamber B, formed of glass. This chamber differs in form fromthat commonly employed and consists of a body portion b, which inclosesthe bend of the filament A, and two extensions b b, which respectivelyinclose the legs thereof. The filament A is attached in the usual mannerto leading-in wires 0 O, sealed in the extremities of the two extensionsb b, the latter being mounted in a socket D, common to both and adaptedto fit a holder.

In working under conditions such as above described any current whichmight seek to pass directly from the one leg to the other of thefilament is intercepted by the air-space E and the two thicknessesofglass forming the inner sides of the tubular extensions b b It is tothis tendency of the current to pass across from the one leg of thefilament to the other that I attribute most of the disintegration whichtakes place in the structure of the filament, the destructive effectincreasing with the resistance ofiered by the filament, according to thematerial whereof it is composed. Ihave, moreover, observedthatthere isfar less heating of the leading-in wires. This may in part beattributable to the presence of a greater mass of comparatively coolglass closely surrounding each wire.

To facilitate the installation of a filament in a vacuous chamber of thekind above described, I adopt the device illustrated in Fig.

3. F is a thin rod of glass bent into the form of an elongated U andhaving its extreme endsffturned outward. In theseoutwardly- 7o turnedends the leading-in wires 0 C are respectively fixed, and the filament Ais then attached to the Wires in the usual manner. With the aid of thisglass carrier F the filament A, with. its leading-in wires 0 C, may nowbe handled with facility and safety, its legs being inserted in theextensions b b, which form portions of the chamber B, until theleading-in wires protrude beyond the extremities thereof, the bend f ofthe carrier F seating at the same time at the point of bifurcation ofthe two extensions. The larger or bulbous end I) of the chamber B isthen partially closed, the chamber is exhausted, and finally it isclosed. The U-shaped carrier F may, if desired, be broken away andremoved after the leading-in wires have been fixed; but if left in thelamp its presence is scarcely perceptible.

Although in the foregoing description I have referred to a filamentousconductor of the ordinary U-shaped pattern, it will be obvious that theapplication of my invention is not confined to filaments of thatparticular form.

What I claim as my invention, and desire to secure by Letters Patent,is-

1. The herein-described method of manufacturing incandescing electriclamps, consisting in forming a bulbous body with two 100 extensionshaving an air-space between them,

then introducing a loop-shaped filament so that the legs thereofrespectively occupy the said extensions and are sealed therein, and 5then closing the bulbous part of the chamber and exhausting the same.

2. In an electric incandescing lamp, a vacuous chamber embracing thebend of the filament, two extensions to said chamber, an airspacebetween said extensions, each extension inclosing a leg of the filament,a socket,

the extremities of said extensions being sep arately mounted in saidsocket.

3. Foruse in mounting a filament in an electric-lamp chamber of thecharacter here- I5 in described, a U-shaped carrier formed withlaterally-turned extremities wherein are fixed the leading-inWires,substantially as set forth.

WILLIAM LAWRENCE VOELKER.

Witnesses:

GEO. P. S. KELSEY, FRANZ HAARHAUS.

